Coating for tablets, capsules, and pills



Patented May 2, 1933 UNITED STATES PATENT omen HILTON wanna, or nn'rao rr, mcnrem coa'rme ron TABLETS,- OAJESULES, mn rims No Drawing.

My invention relates to a new and useful improvement in a coating for tablets, capsules, and pills and particularly to an envteric coating whereby medicament maybe administered in tablet, capsule, or pillform and conveyed to the intestinal tract before t coating is dissolved and the medicament re eased. The purpose of the invention is to provide a coating whereby this result may be achieved.

It is another object of the invention totime be of such a nature that they will bedissolved in the intestinal tract for releasing themedicine. v The coating consists of shellac dissolved in ammonia or 'in ammonia and alcohol. When the shellac is dissolved in ammonia there is a change in character of the shellac,

the exact nature of the change not being fully understood but it is believed that the aliphatic acids of the shellac are neutralized.

It is preferred to employ equal quantities of U. S. P. ammonia and of 95% alcohol. The alcohol is employed merely to facilitate and hasten evaporation and prevent penetratlon of the coating into the tablet, capsule,

or pill. The quantity of alcohol and ammonia used is suflicient for dissolving the- 4 shellac and experience has shown that for most desirable results the shellac should remain in the dissolving solution from twelve to sixteen hours.

The "pill, capsule, or tablet is coated by either havm the com osition vsprayed on thepill or ta let or by t e regular .pan coataa the pill, capsule, or tablet so coated is taken by a person the coating is proof against the acids and "juices of the stomach Application filed June a, 19:30. Serialin. 459,124.

by Letters Patent is:

so that the-pill or tablet will pass substantially intact into the intestines. This is undoubtedly dueto the fact that the coating is alkaline in nature (neutral after volatilization of solvent) and therefore in'addition to the ammonia which is an alkali other suitable alkalies may beused for dissolving the shellac. It is, of course, necessary that ,the alkali used be such that when the pill 'or tablet is taken internally there may be no undesirable action set up. The juices in the intestinal tract being alkaline will act sufficiently quickly upon the pill or tablet to release the medicine so that the patho- I logical, reaction sought may be obtained. This nature of coating is particularly desirable where gland substances and similar ingredients which would be destroyed by the stomach acids and juices are. administered in the form-df a coated pill or tablet.

The proportion of thesolution to the she!- lac would be evident to one skilled in the art, but suflicient of the solvent being necesfor dissolving purposes.

sa l t is desired that pure bleached flake shellac be used free. from arsenic and I have found that for best results 25% solutions of shellac dissolved in equal quantities of ammonia (U. S. P.) and alcohol (95%) are of the correct consistency. A

It is desirable to add the ammonia solution to the shellac first to allow the reaction to take place andthen to add the alcohol.

What I claim as new anddesire to secure as 1. enteric coating for pills and tablets, consisting of the product resulting from shellac dissolved in ammonia.

2. A composition for coating pills and tablets, consisting of the product resulting from shellac dissolved in ammonia together with alcohol.-

In testimony whereof I have signed the foregoing specification.

' MILT ON WRUBLE. 

